1. Field of the Invention
The present invention generally relates to an image forming apparatus.
2. Description of the Related Art
As an image forming apparatus including a printer, a facsimile machine, a copier, a plotter, and a multifunctional peripheral, there has been known an inkjet recording apparatus or the like as an image forming apparatus employing a liquid discharge recording method in which a liquid discharge head (a liquid droplet discharge head) discharging liquid droplets is used as a recording head.
When an image is formed in the image forming apparatus employing the liquid discharge recording method, the image quality may vary greatly depending on the droplet placement accuracy of liquid droplets discharged from the nozzles onto a recording sheet. Namely, when the droplet placement accuracy of the liquid droplets is not sufficient, the image quality may be degraded. Therefore, it may be desirable to accurately determine the position of the recording head.
Further, when, for example, a discharge failure occurs in the recording head, it may also be desirable for a user to easily exchange the failed recording head under the using environment. In this case, it is also desirable that the position of the exchanged recording head be accurately and easily determined with higher repeatability (reliability).
In related art, as a method of improving the position determination accuracy of the recording head when the recording head is to be exchanged, there has been known a method in which a head holder and a carriage are provided, the head holder including plural liquid discharge heads and being detachably supported (held) by the carriage. The head holder further includes a position determination part that is in contact with a position determination reference in the carriage scanning direction and the sheet feeding direction, the position determination reference being provided in the carriage. Then, the position determination part serves as the position determination reference relative to the head holder having the liquid discharge heads (see, Japanese Laid-open Patent Application No. 2011-037235).
In Japanese Laid-open Patent Application No. 2011-037235, however, the position of the head holder relative to the carriage is determined using the position determination surface and the position determination pin. Therefore, the configuration may become complicated. Further, when there are plural head holders, it may be required to have separate position determination parts corresponding to the plural head holders. Therefore, it may become much more difficult to determine the mutual positions of the plural head holders. As a result, it may become difficult to exchange the head holders (recording heads) and place new head holders (recording heads) at the correct (appropriate) positions.
The present application is made in light of the above problems, and it may become possible to easily determine the position of the head holder (recording head) with high accuracy and make it easier to exchange the head holder (recording head).